Fuel supply regulator for gas engines



Sept. 16, 1958 J. H. DAVIDS 2,852,013

FUEL SUPPLY REGULATOR FOR GAS ENGINES Filed Nov. 21, 1956 3 Sheets-Sheet l Inventor JOHN HANS DAwDS 7 p 1958 J. H. DAVIDS 2,852,013

FUEL SUPPLY REGULATOR FOR GAS ENGINES Filed Nov. 21, 1956 3 Sheets-Sheet 2 J Inventor OHN HANS DAVIDS p 16, 1958 J. H. DAVIDS 2,852,013

FUEL SUPPLY REGULATOR FOR GAS ENGINES Filed Nov. 21, 1956 3 Sheets-Sheet 3 A 5 a g B a x v) w '4') Inventor JOHN HANS DAwos United States Patent FUEL SUPPLY REGULATOR FOR GAS ENGINES John Hans Davids, Beloit, Wis., assignor to Fairbanks, Morse & Co., Chicago, Ill. a corporation of Illinois Application November 21, 1956, Serial No. 623,606

11 Claims. (Cl. 123-120) This invention relates to improvements in fuel supply systems for internal combustion engines adapted for operation on suitable gaseous fuels, such as natural gas, propane, or the like. It has particular reference to twocycle gas engines of variable speed type, such as are employed with oil field rigs and the like, and concerns apparatus for changing over engine operation from one type of gaseous fuel to another, as may be required in oil field service.

In engines of the character indicated there are, among other things, two particularly troublesome problems. One involves the inability of the usual type of fuel system to supply the engine with gas fuel at pressure and in quan tities appropriate for effective engine function over the entire speed and load range. A satisfactory solution to this difficulty is afforded by an improved fuel control arrangement forming the subject of a copending application, Serial No. 579,551, filed April 20, 1956, and assigned to the assignee of the instant application, which provides a control provision for adjusting or modulating the gas pressure in direct proportion to engine speed variations.

The other problem, and the one with which this application deals, concerns the inability of such a gas pressure control provision to accommodate quick and easy changeover between gaseous fuels of different heat values.

To illustrate the problem: as shown specifically in said copending application and described generally herein, the control provision for regulating the gas pressure is operable in accordance with engine speed. The air manifold pressure, water jacket pressure, or any engine shaft driven apparatus which reflects the engine speed, is utilized to actuate said control provision for operating a pressure regulator valve device. Since the control provision and valve device are arranged to determine gas pressure in direct proportion to engine speed, it is necessary that they be pre-set to produce proper pressure values at the upper and lower speed limits. Such settings will then permit proper engine operation over its full range, for a given gas fuel of known B. t. u. heat value.

However, in some locations, propane is used when natural gas (methane) is not available. Since these gases have different heat characteristics, a control provision set-up for one will not accommodate the other to produce proper pressure values for engine operation. Thus, the problem of improved engine operation through engine speed regulation of gas pressure, becomes a problem of providing suitable structure whereby the same control provision can be utilized to regulate the gas pressure of gaseous fuels having different heat characteristics.

Accordingly, the general object of the present invention is to afford, in an engine fueling system as hereinabove mentioned, a control provision arranged in the line Y of gas fuel supply, and operable automatically to determine the gas supply pressure at values in direct proportion to engine speed.

More specifically it is an object of the present invention to provide a control provision as indicated, for adjusting or modulating the gas pressure in direct proportion to "ice engine speed variations, which control provision is so constructed and arranged as to be capable of regulating the gas pressure of gaseous fuels having diiferent heat characteristics.

Another object is to afford a control provision for the purpose indicated, whichcoinprises a gas pressure regulator valve device embodying control means normally adjustable for pre-setting the device to establish the pressure of a given gas of known B. t. u. heat value in discharge from the device at the upper and lower speed limits, and engine speed influenced adjustingmeans for said control means, adapted and arranged for effecting adjustments of the control means in direct accordance with variations in engine speed, whereby to produce corresponding changes in the pressure of gas discharge from the device.

A further object is to provide a control provision of the character generally indicated in the preceding object, wherein the control means for presetting the gas pressure regulator device embodies adjustable means whereby a single control provision can be pre-set to accommodate more than one type of gaseous fuel without further or subsequent setting of said device.

A still further object is to provide a control provision of the character and for the purpose indicated, which comprises a gas pressure regulator valve device eifective on gas supply, having control means operable automatically to determine the gas supply pressure at values in direct proportion to engine speed, said control means including spring biased engine speed influenced adjusting means, and stop means for pre-setting the spring bias of said means whereby to establish upper and lower gas pressure limits.

A yet further object is to provide a control provision of the nature indicated in the preceding object, wherein the stop means for pre-setting the spring biased means contemplates multiple stop members such that said control provision can be set up to accommodate gaseous fuels having different heat characteristics, and selector means for'conditioning the control provision for making particular stop members effective in accordance with the type gas to be regulated.

The foregoing and other objects and advantages will I appear more fully, upon consideration of the following description of a presently preferred embodiment thereof as exemplified in the accompanying drawings, wherein:

Fig. 1 is a diagrammatic view showing an engine and gas fuel supply system therefor, with the improved gas pressure regulator provision shown schematically in the system.

Fig. 2 is an enlarged fragmentary view, mostly in section, of the gas pressure regulator provision as shown in Fig. 1.

Fig. 3 is an enlarged sectional view similar to Fig. 2, but in which particular control mechanism has been operated to condition the regulator provision for accommodation of a gaseous fuel having heat characteristics different from the gaseous fuel to be regulated by the mechanism condition of Fig. 2.

Fig. 4 is a graph showing the gas pressure range as to propane and methane, over an engine speed range of 400 to 1200 R. P. M.

Referring to the drawings and particularly to Fig. 1, illustrated diagrammatically at 10 is a variable speed internal combustion engine which may be of two-cycle type, adapted for operation on suitable gaseous fuel, such as propane and methane, or the like. The engine as shown, includes cylinders 11, a I scavenging and combustion air supply manifold 12 in connection to the cylinders, a gas fuel inlet manifold 14 having branches 15 each leading to the cylinder inlet valve (not shown) of the associated cylinder, a cooling water supply conduit 16 in connection to the cylinder jackets 18, and the engine crankshaft indicated bythe broken line 19. Driven from the crankshaft, as by the drive connection indicated by the broken line 20, isa suitable-blower or compressor-22 23, is a water pump 24 suitable to supplya sufiicient quantity of water to the cylinder jackets- 18; und'en'aa pressure which is in direct proportion to engine speed! Connectedto the-engine gasrnanifold 14 is a gas sup-- ply conduit 25 which extends from a source of gas fuel under a predetermined source pressure, such source being;' represented by the tank 26. For the purpose of this disclosure, the tank 26 is to be considered as a source of several. difierent gas fuels (as propaneand methane) of differing heat values, from which any selected oneofsuch gas. fuels is-in. supply to the conduit 25 at, any one time. Included in the conduit 25 are a manual shut-olfvalve 27 and a gas throttle valve 29 illustrated as a butterfly type valve. Throttle valve 29 is controlled or regulated, by a. governor 30 of suitable, well-known form, which is engine driven through connection 31 to the engine crankshaft 19,- and operates in accordance with engine torque output-or loading. The throttle valveand governor are operatively connected by linkage generally indicated at 33, while the governor is settable for load responsive operation. at selected engine speeds, by speed setting mechanism (not shown) embodied in the governor and controlled manually through linkage indi cated at 34.

Arranged in-the gas supply conduit 25' at a suitable point therein which is anterior to the throttle valve 29, is a-pressure regulator valve device generally indicated at40. Device: 40 may be of suitable, readily available type, providing a main gas throttling valve indicated at 41, andajvalve positioning means (not shown) which is controlled-in.a-known-manner by pilot valve control indithe outer end 48 of -the-pilot valve .stem 45. The: com

pression'of spring 46 is adjustable or settable in a manner to be described later; As-is wellknown in regulators of this type, an increase in the compression of spring 46 to effect a corresponding increase in the opposingforcethereof on diaphragm 44, results in pilot valve control of. the main valve-41 to determine-such increased gas pressure at the regulator output to conduit- 2-5 as will rebalance the pilot valve diaphragm, and hence, establish the pressure of'gas fuel in supply to the'throttle valve 29 at a value correspondingto the then adjusted compression setting of the-spring-46. A decrease in-spring compression on thepilotdiaphragm will eifect on theother hand, a correspondingly lower gas pressure in-sup-' ply to the throttle valve 29.

In accordancewith the present invention,- theelfectcf spring 46 on the pilot diaphragmis augmented or modulated by means acting on the diaphEtgm-of the pilot-- valve control to impose a force thereon in direct proportion to engine speed, which results in operation-of=theregulator valve device 40 todetermine the pressure of-gas and lower flanges 51 and 52; respectively, on the pilot valve stem 45; The opposite endof'the lever. is-connected to the movable element or piston 54 (here shown asadiaphragm) of a fluid pressure operated servo-motor indicated at 55, the cylinder or pressure chamber 56 of which is in connection by conduit 58, with the cooling water supply conduit 16 (Fig. 1). The lever 50 is pivotally supported, intermediate its ends, by a fulcrum or pivot member 59 of suitable character, which is positionally adjustable along the lever; as on support 60.

With proper setting of the lever fulcrum 59 and selected adjustment of the 'spring 46, the pressure regulating function of device 40-.may be-determined such that at engineidling speed, for example, the pressure of gassupply to; the; throttle valve 29 will. be at the pressure re- 40 to determine the gas pressure at the value required for'efiective engine operation under the higher speed condition. With increase in speed to the normal maximum enginespeed, the modulating lever device responds in proportiomtocngine speed, tofurther increase the valve diaphragm loading force correspondingly and up to amaximum determined by-the maximum-engine speed, for causing likeincrease in the gas pressure at the throttle valve to values necessary forefiective engine function-at high speeds; Qt course, with decrease in engine speed, the modulating-"lever provision operates in the reverse of the-foregoing, as to cause the pressure regulator to readjust gaspressure-to the required lower values.

It will beappreciatedfromthe foregoing, that by adjusting-'thefunction of the pressure re gulator' 40 through the modulati'ng lever provision-acting in direct proportion to'engine-speed; the'gas pressure-at-the' throttle valve 29 may-be set indirectaccordance with engine speed, such that foranygiven engine speed,- the gas pressure is at the necessary or optimum pressure value required for effective engine operation over-its load range at the given engine speedi Thus, with speed proportioning of gas pressure in this manner, the load limitfor any given engine speed may bedetermined by the gas pressure setting for the given-speed. Consequently, overloading of the; engine at anygiven speed isprecluded by the present gaspressure regulating-provision.

In"'the indicated-embodiment, the adjustable-spring 46 affords afi-xed force =on the-pilot diaphragm of the regulator, variable-invalue according to the adjusted setting of'the-spring, while the pivoted lever-provision provides a modulating force automatically varying in proportion to engine speed; The; force ratio of the lever provision is-adjustable, as previously indicated, by-varying the position-of the lever fulcrum 59; whereby to permit of adjustments in the operation of the'provision to accommodate given-conditions ofa' givenengine installation, and'lto adapt-the modulating control to the B. t. u; heat value of thegasfuel. The manner of efiecting the indicated adjustments'will now be described.

Referring to Figs. 2 and 3; there is shown enlarged detailedviews ofthe control provision, indicated generally by reference .numeral' 70, which acts to control'the pressure regulator va-lve device 40 whereby to regulate the gas pressuresupply to the, engine. in direct proportion to the engine speed. Fig. 2" shows said control provision conditioned or set up for use with a particular gaseousiuel, for example, propane, whereas Fig. 3 shows said control provision set-up for use with a different gas, such ,as methane, In both views-like partsare designated by the same reference numeral. As indicatedga base or. I

uPRQ 1 IIIlb.BL 71 is, provided, near one end thereof, with a bore 72;.into, which seats a,v hubv Pplll0l1f74: of I a flange memberj75,',saidjflange member beingssecuredsto said base in any suitable manner. Said flange member sesame cooperates with an underslung housing 76 to afford a chamber 78, in which is disposed diaphragm member 44, secured at its outer periphery between the flange and the housing, as at 79, and mounted on pilot valve stem 45, said valve stem extending through a bore 80 in flange hub 74 to termination in spaced apart flange portions 51 and 52 and stub or end portion 48. Said pilot valve stem is integral with a pilot valve 42 (shown dotted in Fig. l), which operates valve positioning means '(not shown) in a well known manner to control gas throttling valve 41.

As previously mentioned, the diaphragm 44 is subjected on its underside to the pressure of gas fuel at the outlet side of main valve 41, and on its upper side to an opposing pressure provided, in part, by spring 46 in compression against the outer end 48 of the pilot valve stem 45. Said spring is contained between the stem outer end 43 (against flange 51) and a cup-like member 82, all of which are disposed within a housing member 83 mounted on the base 71. The upper portion of said housing is provided with a threaded bore 84, aligned with the valve stem axis, and having a bolt or stop member 86 threaded therethrough. The end portion 87 of bolt 86 fits into and abuts the cup-like member 82, whereby movement of said bolt, in or out, will cause like movement of said cup-like member, thereby increasing or decreasing the compression factor of spring 46, respectively. A lock nut 88, in threaded engagement with bolt 86, provides means for maintaining said bolt in any degree of adjustment as may be required.

It should be obvious that movement of bolt 86 inwardly will cause an increase in the compression of spring 46 to effect a corresponding increase in the opposing force thereof on diaphragm 44, resulting in pilot valve control of the main valve 41 to determine such increased gas pressure at the regulator outlet to conduit 25 as will rebalance the pilot valve diaphragm, and hence, establish the pressure of gas fuel in supply to the throttle valve 29 at a value corresponding to the then adjusted compression setting of the spring 46. A decrease in spring compression on the pilot diaphragm will effect, on the other hand, a correspondingly lower gas pressure in supply to the throttle valve 29.

As before described, the effect of spring 46 on the pilot diaphragm is augmented or modulated by means acting on the diaphragm of the pilot valve control to impose a force thereon in direct proportion to engine speed, which results in operation of the regulator valve device 40 to determine the pressure of gas supply to the throttle valve 29 at pressure values varying in direct proportion with engine speed variations. The modulating means is comprised of the fulcrumed lever 50 having one end 90 extending through an opening 91 in the housing 83 to engagement between upper and lower flanges 51 and 52, respectively, on the pilot valve stem 45, said one end preferably being bifurcated so as to insure a positive engagement with said stem. The other end 92, of the lever 50, is provided with an adjustable member or bolt 94 which depends from said lever sufliciently to abut the stem portion 95 of a movable element or piston 54 (here shown as a diaphragm) of a fluid pressure operated servomotorindicated at 55. 'As previously mentioned the servo-motor chamber 56 is in connection by conduit 58 with the cooling water supply conduit 16, and any pressure change of said water supply. will be reflected by movement of stem 95 to cause movement of lever 50, with subsequent effect at lever end 90 on the pilot valve stem 45.

It should be apparent that the degree of movement of lever end 90 responsive to movement of lever end 92, is dependent on the position of fulcrum 59 relative to lever 50. For purposes to be later described, the fulcrum member 59 is adjustable, and in the following manner. Said fulcrum member is cylindrical in shape, having its 6 outer surface formed to provide a main cylindrical sur-' face 97, and a reduced cylindrical portion 98, thereby providing a shoulder 99. Support member 60 is formed to provide a cylindrical bore having a main cylindrical surface 102 and a reduced cylindrical surface 103, thereby forming a shoulder portion 105. As shown in the drawings, the cylindrical outer surfaces of fulcrum member 59 are so related to the cylindrical surfaces of the bore as to form 'a cylindrical pocket or space 106 between the shoulders 99 and 105. Disposed in said cylindrical space 196 is a helical spring 107, of the compression type, which urges said shoulders apart, i. e., the-spring tends to move fulcrum member 59 outwardly, or to the right as shown in the drawings. Opposed to this spring-urged outward movement of the fulcrum member, so as to limit said movement, is an adjustable stop member 198, comprising a boss or flange 109 fixed to base plate 71, having a bolt 110 threaded therethrough and provided with a set-pin 112 (indicated in outline) for locking said bolt in any desired position of adjustment. It is apparent then, that with member 59 in abutment with belt 110, movement of the latter will resultin movement of fulcrum member 59 whereby to change the length and effect of lever arms 98 and 92, one to the other.

As will be described more fully later, adjustable stop member 86 is preset to produce the proper pressure value at the lower speed limit, stop member 108 is preset to determine fulcrum positionment for the proper pres sure value at the upper speed limit, and lever 50 acts in response to changes in engine speed to produce, in direct proportion thereto, proper intermediate pressure values, for a given gas of known heat value.

Referring again to Figs. 2 and 3, support member 60 has formed as a part thereof, an upright plate 114, to which are pivotally mounted upper and lower bell cranks, 115 and 1156, respectively. Upper bell crank 115 has one arm 118 extending towards the lower bell crank 116, while said lower bell crank has one am 119 extending toward said upper bell crank, said arms 118 and 119 extending in an over-lapping relation, adjacent a cam member 120, said cam having a handle 122 operatively associated therewith for rotary movement of said cam to either of two positions, as indicated.

Upper bell crank 115 has another arm 123 which extends over housing member 83, and is provided with an adjustable bolt or stop member 124, threaded therethrough, having a set-screw 126. Stop member 86, formed to provide a central bore 127, has a rod 128 disposed therein and which bolt 124 may abut when bell crank 115 is in the proper position (Fig. 3). With bolt 1Z4 properly adjusted, movement of bell crank 13.55 to the position shown in Fig. 3, will cause rod 128 to move beyond the end 87 of bolt 86, thereby acting upon cup-like member 82 to effect the compression factor of spring 46. In this position, adjusting movement of bolt 124, in or out, will cause like movement of said cup-like member, thereby increasing or decreasing the spring compression factor, as the case may be.

Lower bell crank 116 has another arm 130 which extends to a position adjacent the fulcrum 59, and which is provided with an adjustable bolt or stop member 131, threaded therethrough, having a set-screw 132. When bell crank 116 is in the position shown in Fig. 3, adjusting movement of bolt 131, in or out, will cause like movement of said fulcrum member, thereby changing the lever arm ratio of lever 50.

As shown in the drawings, the bell cranks 115 and 116, are under bias through springs 134 and 135, respectively, so as to insure positive and immediate response of said bell cranks to movement of the cam member 120.

Also, it should be noted that due to the cam shape, said I cam is either effective or ineffective as regards the bell cranks, and is positionable through handle 122 to condition the elements, either as shown in Fig. 2, or as shown in Fig. As previously pointed out, andasnowwill be, described, Fig. 2; showsthe control provisioncondi with the engine running. at no load, it is found whenv using propane that, the gas pressure in supply. to the engine throttle valve should. closely approximate 10 p. s. i. g. at the minimum engine, speed of 400 R. P. M., and about 25 p. s. i. g. at themaximum speed of 1200 R. P. M. The curve P as shown in the graph of Fig. 4, indicates the pressure range-for propane, over the engine speed range of 400 to 1200 R. P. M., Withthegas pressure-in p. s. i. g. being the headerpressure in supply to the throttle valve 29.

Now with gas fuel supplied to the pressure regulator device, at. say a minimum of 50 p. s. i. g., the engine is started and operated under no load at. 400 R. P. M. Referring to Fig. 2, the regulator spring 46 is adjusted by movement of stop member 86 until the spring pressure plus the additional pressure imposed by the speed responsive lever 50 then effective on the pilot diaphragm 44, is such as to set the regulator for determining the gas pressure at the throttle valve, (which may. be observed, Fig. l, on a pressure gauge 136 in the conduit 25), at the desired value of 10 p. s. i. g. whereupon, the engine speed is increased to 1200 R. P. M. atno load. If the pressure on gauge 136 is greater than the desired 25p. s.,i. g. the lever fulcrum 59 then is moved in the direction away from the lever end which is in engagement with the pilot valve stem. This adjustment is made by threading out the bolt 110 whereby action of spring 107 causes fulcrum member 59 to move outwardly, or to the right as shown in the drawings. On the other hand, if the pressure is below 25 p. s. i. g, the fulcrum is moved inthe opposite direction, or towards the lever end which is in engagement with the pilot valve stem, as by threading in'bolt 110.

After such'fulcrum adjustment, the engine is again at 400 R. P. M., and the spring 46 then adjusted, if necessary, untilthe gauge pressurereadslO p. s. i. g. Following this, the engine speed is increased to 1200 R. P. M;, and the gauge pressure is, thenobserved. If the pressure is substantially at 25 p. s. i. 'g., the regulator is in proper adjustment for engine operationyover its full speed and load range, with the lever control 50 acting to regulate the pressure of gas supply to the throttle valve within the indicated pressure range, in direct proportion to engine speed. If, however, the gas pressure at 1200 R. P. M. under-the no load condition of'the engine, is not at the required 25 p. s. i. g. value, then the fore-going described adjustment steps must be repeated until the required pressure conditions are obtained.

When the above adjustments have beenmade, the control provision 70 is set up to regulate one gaseous fuel, as by example, propane. To condition the control provision for-another gaseous fuel, say methane, while yet maintaining the proper settings for propane, requires that handle 122' be rotated clockwise, to the position indicated in Fig. 3. Such handle movement causes like movement of cam member 120, which actuates bellcranks 115 and 116 through the arms 118 and 119, respectively, to the positions shown.

Movement of hell crank-arm 123 causes bolt 124 to contact rod 128, and upon full actuation of said arrn, said rod extends beyond the end 87 of stop member 86'. As shown in Fig. 3; rod128then abuts cup-like member 82 and-moves it away'frornrcontactwith stop member 86, thereby effecting a new compression adjustment of spring 46 independent of the setting of member 86, and

withou sturbin.gth tsetting o v the la ter. l mov ment otbelli r n sarm caus sbolt 131 to,con t t fulcrum member 5.9., QQQLUR'QH full ct ion f. s id m, oLmov aid fulc um. away fmm wp memb r lltlandtoward theleyer, end? which is: in;engagement with the pilotv lve. rn.

Assuming, theengine. installation pr y. e r b d n with. the engine. ru i ng. at no load, it is foun whenusinem thauehthatth gasnressur n upp y. to the engine throttle valve should approximate 12 p. s. i. g, at the minimumenginespped of 400 R. P. M., and 37 P.- grat the maximu rn speed of 1200 R. P. M. Asv shown in,Ei g, 4,; he curve,Mzindicates the pressure range for me haue ou his. s m 400m 200 RR M- pe d a e he ng ne- With sasfueL -pp ed. to the pres.- s re gul or evic at liem nim mb 50 P -s, hsengin isstart d and ope ated n rlie l at R M. As hownin i grfir he r g la r pring.46 is. adiust d y movement f stop mem er. 12 hich acts through rod l28 to move cup-likernember 8 2, untilthe springp ressure plus the additional pressure imposed by the. speed responsive lever 50 then effective on the pilot diaphragm 44, issuch asto set the regulator for determining the, gas pressure at the. throttle valve, at the desired value of 12p, s. i g; The engine speed'is now increased to IZOOR. 'P, M, at no load. If the pressure on gauge. 13.6 is greater than the desired 37 p. s. i. g., the lever fulcrum 59" then is moved in the direction away from the lever end which is,in engagement with the pilot v lv st ni. Th adiustmentci a y threading. the heltlfil h rebv ion p i 107 causes um memb r to. mov ou y the opposite direction or'inwardly, as by. threading in bolt. 1 3 1. After such'fulcrumadiustment, the engine is again run a t 400j R. R. Mi, and'spring 46.'then readjusted if necessary, until the gauge pressure reads 12p. 5. i. g. Theengine speed'is then increased to 1200' R. P. M;,

and if. thepressureis substantially at 37p. s. i. g'., the

regulator is properly adjusted-1 for engine operation over its full. sp edandi-load r nge w the gasr sure at 1200' R. P. under the noload condition of theengine, is notat therequired 37 p. s. i. g. value, ,then the. for going, des ribed j s ent st ps must be r Pfiatcdhuntil thereguired'pressure conditions are obtained.-

With the above adjustmentsjrnade', ,the control provision 70 as shownin Big, 3 isjsetup to regulate. one gaseous previously described, the control provisionas SIQQ WHiQFigIZJ'iS set up-for a different gasf el, s. met ane.

eons fuel; propane for example. It will be observed now that thesettingsof'stop members 86 and 110, as provided for. regulationof, methane, are independent of thesettings of stop members 12 4.and- 131, provided for regulation ofpropane. Thus, through manipulation of handle 122, the. control provision may be conditioned selectively for regulation ofoneor the other of two different gaseousfuels, as circumstance may require.

In field'operationwlrere a suitable supply of methane;

is available, the control provision would be in thecondition shown in Fig. 3; affording engine supply of gas fuel at proper pressures over, the full speed and load range with lever control SOacting to regulate the'gas supply pressure to thethrottle. valve within the'indicated range, in direct. proportion toengine speed. Should there be an interruption or failure in the supply of methane, movement ofhandlelZZto-the position shown in Fig. 2, would condition or setupthe control provision for proper regulation of the gas supply pressure onavail-t However, if the pressureis' below 37' p. s, i. g the fulcrum is moved ininvention provides a control provision operable automatically to determine the gas supply pressure at values in direct proportion to engine speed. Furthermore, said invention provides suitable structure whereby the same control provisioncan be pre-set to accommodate any two difierent gaseous fuels without further or subsequent setting of said control provision other than operation of selector means for determining the setting to be made efiective for either of two given fuels.

While the foregoing specification sets forth the invention in somewhat specific detail, it is to be understood that many variations and modifications may be resorted to without departing from the broad aspects of the invention as defined by the following claims.

Having now described the invention, what is claimed is:

1. In an internal combustion engine operable on gas fuel and having a fluid pressure system in which the pressure of fluid therein is proportional to engine speed, a fuel supply system including a conduit for engine delivery of gas fuel under pressure, a throttle valve in said conduit, a pressure regulator device in the conduit, said device including a control element conditionable for regulating the device to determine the pressure of gas fuel in supply to the throttle valve, settable adjusting means for conditioning said control element, settable auxiliary means responsive to the fluid pressure in said fluid pressure system, operable on said control element to alter the conditioning thereof by said adjusting means, in accordance with engine speed, adjustable stop means for said auxiliary means, and lever means operatively associated with said adjusting means and said adjustable stop means, jointly, for determining the settings thereof.

2. In an internal combustion engine operable on gas fuel and having a fluid pressure system in which the pressure of fluid therein is proportional to engine speed, a fuel supply system including a conduit for engine delivery of gas fuel under pressure, a throttle valve in said conduit, a pressure regulator device in the conduit, said device including a control element conditionable for regulating the device to determine the pressure of gas fuel in supply to the throttle valve, settable adjusting means for conditioning said control element, first lever means operatively associated with said adjusting means for deterining the setting thereof, settable auxiliary means responsive to the fluid pressure in said fluid pressure system, operable on said control element to alter the conditioning thereof by said adjusting means, in accordance with engine speed, adjustable stop means for said auxiliary means, second lever means operatively associated with said adjustable stop means for determining the setting of the auxiliary means, and cam means for actuating said first and second lever means.

3. In an internal combustion engine operable selectively on one or another gas fuel and having a fluid pressure system in which the pressure of the fluid therein is proportional to engine speed, a gas fuel supply system including a conduit for engine delivery of gas under pressure, a throttle valve in said conduit, a fuel pressure regulator in the conduit and adjustable for determining fuel pressure in supply to the throttle valve, said regu-' lator providing an adjustment control element, settable spring means imposing a control force on said control element, at least two alternatively effective spring setting means for said spring, pivotal lever means in operative connection to said control element and effective, in accordance with variations in fluid pressure in said fluid pressure system, to regulate said control element, said lever means including a selectively positionable fulcrum lever support, at least two alternatively effective position determining means for said fulcrum lever support, and means operable selectively for simultaneously rendering one of said spring setting means and one of said position determining means effective and ineffective.

4. In an internal combustion engine according to claim gamers 1O 3, wherein the said selectively operable means includesa pair of pivotal lever elements and lever actuating cam means common to said lever elements.

5. In an internal combustion engine operable selectively on one or another gas fuel and having a fluid pressure system in which the pressure of the fluid therein is proportional to engine speed, a gas fuel supply system including a conduit for engine delivery of gas under pressure, a throttle valve in the conduit, a fuel pressure reguator in the conduit and adjustable for determining fuel pres-sure in supply to said throttle valve, s'aid regulator providing a pressure adjustment control element, settable spring means imposing a control force on said control element, regulating means operable in response to fluid pressure variations in said fluid pressure system, for imposing an additional control force on said control element varying in proportion to engine speed variations, said regulating means including a pivotal lever engaging said control element and a movable lever fulcrum support positionable along the lever, adjustable means for determining one position of said fulcrum support along the lever, a pivotal member including an adjustable element for determining another position of said fulcrum support along the lever, an adjustable element for determining one setting of said spring means, means including a second pivotal member and an adjustable element for determining another setting of said spring means, and an actuator common to said pivotal members.

6. In an internal combustion engine selectively operable on any one of several given gas fuels differing in heat value, a gas fuel supply system for the engine, said system including a gas pressure regulator adjustable for determining the gas pressure in the engine supply system, said regulator having an adjustment control element, first adjustable means imposing a control force on said control element, second adjustable means including an actuator subject to engine speed variations, for imposing on said control element an additional control force variable in proportion to variations in engine speed, means operatively associated with each of said first and second adjustable means for determining a first adjusted condition of each thereof whereby to condition the regulator for determining the pressure of one given gas fuel in the engine supply system, and other means operatively associated with each of said first and second adjustable means for determining a second adjusted condition of each thereof whereby to condition the regulator for determining the pressure of another given gas fuel in the engine supply system.

7. In an internal combustion engine according to claim 6, characterized further by means operable selectively for rendering the said other means effective and ineffective to determine the said second adjusted condition of the said first and second adjustable means.

8. In a fuel supply system for an internal combustion engine operable on gas fuel and having a fluid pressure system wherein the fluid pressure is proportional to engine speed, a pressure regulator device in the fuel system for determining the pressure of gas fuel supply for the engine, said device including a control element regulatable to condition the device for determining the gas supply pressure, adjustable spring means imposing a control regulating force on said control element, adjustable auxiliary means imposing on said control element an additional regulating force proportional to engine speed, the last said means comprising a pivotal member in operative engagement with said control element, a positionable fulcrum member pivotally supporting said pivoted member, spring means urging said fulcrum member in one direction, first adjustable stop means operatively disposed adjacent the fulcrum member in opposing relation to said spring-urged fulcrum movement, second adjustable stop means operatively disposed adjacent the fulcrum member in opposing relation to said spring-urged fulcrum movement, lever means operatively associated with said second 11, adjustablestop, means for moving;saidrsecondnadjustablstop means into andsoutofxan effective r'elation.,with,said; fillcrl ml-membter, ,and fluid pressureoperated. means; connectedgto the. pivotal member and responsivetofluid'pre's: sure ,variationsin saidrfiuid pressure 'system,.sforfl pivotally actuating said pivotalfmember.

9r. Inrasfuel supply systemior an,internal combustionenginewoperable. on .gas fuelandshavingia fl'liid pressure system wherein thelfiuid pressure is proportional gtoengine. s eed; .a pressure-reg'ulator device in the, fuel system for determining theipressure of gasifuelsupply for the engine, said I devices including av control element; regulatable to condition the,,device for determining the; gas supply pressii're, a,jspring member, ton imposing a control regulating force on s'aidcontrol element, adiusting means associated With'jsaid spring member for altering its control regulating force, saidlast means including a first adjustable stop member for operative engagement with saidspring memher, a movable rod extending through saidstoprmember, a second adjustable stop.member operatively disposed adjacent saidrod and movable into abutment with the rod, eifectiveto displace the rod into an engagingrelation with the spring and thereby to move said spring away from engagement'with the first adjustable. stoprmember, lever means operatively associated with the second adjustable stop member for moving said second adjustable stop member intoand out of"displacement efiecting relation with said rod; andadjustable.auxiliarvmeansimposing an additional regulating force on said control element, said auxiliary means including-a pivotal lever in operative justable intermediate the ends-of the lever, and 'lever '01 erating means connected to the lever and operableauto connection to; said control element, lever pivot meansad zifififigzz" matically. in. accordancewithrfluid pressures-variations; in.

saidflnid pressure system; 7

1Dl.In;a fueLsuppl pressureregulator having,a-.pres: sureadjustments control. element, the. combination with said; regulator of. as settahle springs imposing a control force on said regulator. control element, ant adjustable memberfondetermining ,one control setting of said spring,

separate means includingan adjustable element, operable to andfrom an eifectivepositiondetermining another controlsetting of'saidispring, means including a pivotalllever in engagementwith saidcontrol element, ,for imposing an additional control force on the. control element, and a lever fnlcrum support positionable alongsaid lever for regulating the control force imposing efiect'of the lever on said'controlelement, adjustablemeans for determining oneposition of said fulcrum support along the lever, sep; arate meansincluding anadjustable element, operable to and=ffom an efrectiv'e position determining another posi' tion. of "the fulcrum support along the lever,,an'd means for operating the saidseparate means to and" from said efiective positions thereof:

' ll. Th'ecomb'ination as defined'by, claim 10, wherein the last said means includes .an actuating member common to the said separate vmeans for conjoint operation of'the separate means selectively'to andfrom the said effective positions thereof:

References-Cited in'the file of this patent UNITED STATES PATENTS.

Kenwortliy-et'al Jan. 19,1954- 2682,8661; Rhoades. July 6, 195:4 2,780,209 Renken Fat- 1957 

